Relieving attachment for lathes



Filed u arch' so) 1939A shuts-sheet lNVENToR.- w\L\ \AM F. @Roline mid ATTORNEY.

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May 28, 1940 w. F. GRoENE mIEvIHG TTACEERT FOR mms Filed lawn 3o. 19:59 4 sheets-sheet 2 INVENTOR. WILURM RGROEINE v .BY l :MMA

ATTORNEY.

May 28, 1940-f. w. r-'. GROENE 2,202,287

RELIEVING ATTACHHENTFOR LATHES Filed uarcn so, 1939' 4 snee'ts-sneef s 2 N Y lo wl-fak i *l* ,b g [l :g E a il a@ i d- 'I 2 WITNESS- wmJnM- ausge @fwf/ ATTORNEY.

May 28, 1940. 2 l w. F. GROENE 2,202,287

nnLIavING museum For: Lnmss Filed March so, 1959 4 sheets-sheet' 4|' NVENTOR wrmess. :wnmm fac-Rome f AT'TQRNEY- v Patented May 28, 1940 IUNITED "STATES 2,202,287 l anun-WING ATTACHMENT Foa LATnEs' William F. Groene, Cincinnati, Ohio, assigner to The R. K. Le Blond Machine Tool Company, Cincinnati, Ohio, a corporation oi' Delaware Application March 30, 1939, Sei'lal N0. 265,002

5 Claims. (Cl.'8219) This invention pertains to relieving attachment for lathes and related machine tools. In attachments of this character heretofore used, the direction of feeding the tool to the work has always 5 been effected in the same plane in which the reciprocation of the tool takes place to produce the relief on the cutter, tap, etc., to be relieved. Becauseof this construction it has always been necessary in the past to use form tools or cutters l0 which were preshaped to the exact contour to be produced on the work piece. These cutters were fed perpendicular to thework surface to be relieved in a plunge cutting operation and parallel'with the reciprocating relieving attachment. 1'5 As a result great strain is produced inthe work vp iece and the necessarily very slow feed results in slow production and inaccuracies inthe work piece. Particularly is this former method of plunge cutting Y when .relieving unsatisfactory 20 where relatively large portions of the work pieces wherein the direction of relieving and direction of feeding of the cutting tool could be effected in an infinite variety of different `directions it would be unnecessary tol utilizev form'cutters and plunge 3'0' cutting feeding movements. Any single point cutting tool could be used,` thus greatly minimizing? strains set up in the worlc piece during the turning and relieving'operation resulting in a much greater accuracy and better'iinish on-the s completed Vwork piece. And notonly this, but by this arrangement it is -now practical to relieve coarse lpitch taps or the like ofa size and limberness which it was not possible to do formerly.

Other features and advantages of this inven- 0 tion will appear in the vdetail description of the drawings inwhich: v

Figure I is a plan view of afrelieving attachment incorporating the features of this invention.

Figure II is a vertical section on the line II-II Figure DI is a vertical section on the line 111- IIIofllgureI.A v l .Figure IV is a vertical section on the line 'IV- IV'of Figure I.

'50` Figure Vis a diagrammatic layout showing the '55 carried on a swivel mounting 2 of the crossl slide suitable dovetail guideways 9 on the base I is the frame I0 which may be actuated in feeding movements on said guideways 9 by applying a suitable wrench to the squared end portion II of the relieving attachment feed screw I2 which operates Y10 in the nut I3 fixed to the base I and is journaled against axial movement in the plate I4 which is xed to the cover plate I5, thisplate in turn being vsecured tightly to the frame III by the screws f I6.

Slidably mounted in the frame II) in a guide- 2.15

way provided by the surfaces Il, I8, I9, and 20, is

l the reciprocating bar2l having a wrist pin 22 fixed therein, a connecting rod 23 being pivotally mounted about said wrist pin and journaled at its other end on the eccentric portion 24 of the ec- I20 centric rock-shaft25. The rock shaft -25 vis journaled at its lower end in a bearing 26 .in the frame I0. Its upper end 21 is taperedand is xed in the bushing 28 .which in turn is journaled in the bearing 29 forme'd in the plate I5. On topof the l25 bushing 28 is xed the actuating dog 30 by suit'- able T-slot bolts 3|. The actuating dog 30 has a contact point 32 which is held in contact with the periphery of the operating cam 33 by means of tension spring 34 connected to the arm 35 of the 3 0 dog 30 -and to the pin 36 fixed in the plate I5. 'Ihe cam 33 is fixed on the shaft 31 journaled in t `theplate I5 -aid is ydriven bythe shaft 38 from 1,596,827 dated August 17, 1926. A compression spring 4Ilv carried in the frame III and bearing against the lower4 projecting end. 22a ofr the wrist 40 pin 22 serves to keep out back lash in the conv-necting 'rod bearings on the wrist pin 22 and eccentric 24 to' eil'ect smooth and'uniform reciprocation in thebar 2I.A 'Thus .with this arrangement the bar 2l. may be reciprocated to effect 4,5 relieving movement at any position at which the attachment may be yseton the swivel mounting 2.

'I'he .feed screw I2 does not partake of this reciprocating movement and is, therefore, readily operable during the reciprocation of the bar 2l' and.j50

its indicating dial IIa consequently easily readable during operationof the device.

On the frame III is xed the swivel base 4|.by

the screws 42 which has `a slotted portion inits -lower-V face formed bythe surfaces 43, 44, and 45 to 55 accommodate the reciprocating bar 2|. On top of this swivel base 4I is mounted the swivel plate 46 which has a downwardly projecting integral boss 41 which'is adapted to rotate in a bore 48 passing through the swivel base 4| into its slotted portion above described. This swivel plate 46 may be locked in any desired position on the swivel base 4| by suitable clampingbolts 49. In the` swivel plate 46 is mounted the reciprocating tool holder 50 in appropriate dovetail guideways 5| which carries a cutting tool 52 held in place by the usual set screws 53.

A plate 54 fixed to the reciprocating bar 2| by the screws 55 has an upstanding integral boss 54a. on top of which is carried a roller 56 which nicely fits between the faces 5 1 and 58 of the cam slot 59 formed in the bottom of the tool holder 50. It can thus be seen that by this arrangement the tool holder 50 may be reciprocated for any position at which the swivel plate 46 might be set so that the reciprocating relieving movement may, be effected in the tool holder 50 in any direction relative to feeding of the tool to the work as effected by the actuating feeding screw Il.

Figure V shows a typical mode of operation of this invention as for example when used to relieve a large coarse thread tap 60 having a V- thread with sides 6| and 62. A single point cut.

ting tool 52 is shown applied to machine the reliefon the side 6|. In order to do this the base I of the device is adjusted so that the direction of feeding movement of the frame I0 on the dovetail guidewayS takes place parallel with the side 6| of the tap, the tool 52 feeding from 52a to 52h in the direction indicated by the arrow 63. The swivel plate 4B is adjusted and clamped on the swivel base 4| so that the reciprocating relieving motion 52e of the tool takes place substantially perpendicular to the axis of rotation of the work or in the direction indicated by the arrow 64 so as to develop a truly relieved surface on the side 6| though a single point tool is used. The tool 52 is thus fed in a direction angularly related to the direction of relieving motion effected in the cutting tool during the relieving operation. y l

Thus in this invention the following significant features have been developed in a relieving attachment:

(a) Feeding and reciprocating relieving movements which may be effected in different directions.

(b) Feeding and reciprocating relieving movements which may be effected in an infinite variety of angularly related directions.

(c) A single point cutting tool is all that is required to relieve any type of work surface to be cut.

`.(d) Greatly reducesv strain to the work piece in any type of work to be relieved.

(e) Makes possible heretofore impractical machining of large coarsethread .taps and the like.

(f) All rapidly reciprocating parts of extremely light though rigid construction providing eilicient application of the relieving motion to the cutting tool without vibration in the apparatus.

(g) 'I'he feeding of the lcutting tool relative to the work is effected at a point (squared end of the feed screw I2) which does not have the bothersome and annoying reciprocating relieving movements as in former devices which makes it diflicult to operate the feeding screw and to read its indicating dial Aduring the machining operation.

Having thus fully set forth and described my invention, what I claim and desire to secure by United States Letters Patent is:

l. In a relieving attachment for lathe, a base mounted to swivel on the cross slide of said lathe, a frame slidably mounted on said base, means on said frame for feeding said frame relative to a work piece in said lathe, a tool holder mounted to swivel in a horizontal plane on said frame, a cutting tool in said tool holder, a reciprocating bar slidably mounted in said frame, and cam 4means interconnecting said bar and said tool whereby reciprocation of said bar effects reciprocation of said tool holder in any adjusted position of said tool holder on its swivel mounting.

2. In a` relieving attachment for lathe, a base mounted to swivel on the cross slide of said lathe, a frame slidably mounted on said base, means on said frame for yfeeding said frame relative to a work piece in said lathe, a tool holder mounted to swivel in a horizontal plane on said frame, a ycutting tool in said toolholder, a reciprocating bar slidably mounted in said frame, cam means interconnecting said bar andsaid tool `whereby reciprocation of said bar effects reciprocation of said tool holder, and eccentric and connecting rod mechanism actuated by the transmission mechanism of said lathe for actuating said reciprocating bar.

3. In a relieving attachment for lathe, a base mounted to swivel on the cross slide of said lathe, a frame slidably mounted on said base, means on said frame for feeding said frame relative to a work piece in said lathe, a tool holder mounted to swivel in a horizontal plane on said frame, a cutting tool in said tool holder, a reciprocating bar slidably mounted in said frame, cam means interconnecting said bar, and said tool whereby reciprocation of said bar effects reciprocation of said tool holder, eccentric and connecting rod mechanism in said frame connected to said reciprocating bar, and cam and dog mechanism actuated by the transmission mechanism of said lathe for operating said eccentricand connecting rod mechanism to effect reciprocation of said bar.

4. In a relieving attachment for lathe, a base `mounted to swivel on the cross slide of said lathe,

a frame slidably mounted on said base, a screw journaled against axial movement in said frame and operating in a nut afxed to said base for effecting feeding of said frame relative to a work piece in said lathe, a tool holder mounted on a swivel plate carried on said frame, means permitting reciprocating movementof said tool holder on said plate, a tool in said tool holder, a reciprocating bar mounted in said frame, a cam roller carried on said bar and operating in a cam slot in said tool holder whereby reciprocating movein said tool holder for any adjusted position of said swivel plate on said frame, and means for effecting reciprocation of said bar from the lathe transmission mechanism.

5. In a relievingattachment for lathe, a base mounted to swivel on the cross slide of said lathe,

, a frame slidably mounted on said base, a screw ment in said bar effects reciprocating movement tric rock shaft, a connecting rod connecting the eccentric portion of said shaft with'said .recipro l cating bar, a dog xed on said rock Shaft, a cam for actuating said dog mounted on a cam shaft, and means for driving said cam shaft from the lathe transmission mechanism.

WILIJAM F. GROENE. 

